Control device for projector film stripping and threading mechanism

ABSTRACT

A self-threading motion picture projector includes a control device which latches a film stripping and threading mechanism of the projector in its active position wherein it is effective to feed film from a roll of film supported by the projector. When the leading end of the film has entered a film gate of the projector and has been engaged by a film-advancing member (which advances the film at a rate faster than the film stripping and threading mechanism), the control device is unlatched in response to the resulting tension of the film between the gate and the supply reel, thereby causing the stripping and threading mechanism to return to its inactive position so that the film can be projected. In the event the mechanism is moved to its active position when there is less than a minimum length of film on the supply reel (i.e., the film roll is of less than a minimum diameter), or if there is no supply reel on the projector, the control device will not latch the film stripping and threading mechanism in its active position.

United States Patent 1 Bunting Aug. 7, 1973 CONTROL DEVICE FOR PROJECTORFILM STRIPPING AND THREADING MECHANISM [75] Inventor: Leslie J. Bunting,Rochester, N.Y.

[73] Assignee: Eastman Kodak Company,

- Rochester, NY.

221 Filed: Apr. 23, 1971 [21] Appl. No.: 136,803

[52] U.S. Cl. 242/192, 242/187 [51] Int. Cl. G03b l/58, B65h 25/28 [58]Field of Search 242/195, 192, 197, 242/205, 186, 187, 188; 352/72, 157,158

[56] References Cited UNITED STATES PATENTS 3,506,345 4/1970 Wells242/197 UX 3,552,683 1/1971 Bundschuh et al. 242/192 PrimaryExaminer-Louis R. Prince Assistant Examiner-John M. Jillions Att0rney-W.H. J. Kline and Milton S. Sales [57] ABSTRACT A self-threading motionpicture projector includes a control device which latches a filmstripping and threading mechanism of the projector in its activeposition wherein it is effective to feed film from a roll of filmsupported by the projector. When the leading end of the film has entereda film gate of the projector and has been engaged by a film-advancingmember (which advances the film at a rate faster than the film strippingand threading mechanism), the control device is unlatched in response tothe resulting tension of the film between the gate and the supply reel,thereby causing the stripping and threading mechanism to return to itsinactive position so that the film can be projected. In the event themechanism is moved to its active position when there is less than aminimum length of film on the supply reel (i.e., the film roll is ofless than a minimum diameter), or if there is no supply reel on theprojector, the control device will not latch the film stripping andthreading mechanism in its active position.

6 Claims, 4 Drawing Figures N EB 3.750.975

SHEE! 1 0F 2 LESLIE J. BUNTING INVENTOR.

I BY FIG. 2

ATTORNEYS PAIENIEUAUB 1m 3.750.975

SHEET 2 0F 2 LESLIE J. HUNTING INVENTOR.

BY wgsww ATTORNEYS CONTROL DEVICE FOR PROJECTOR FILM STRIPPING ANDTHREADING MECHANISM BACKGROUND OF THE INVENTION 1. Field of theInvention The present invention relates to self-threading motion pictureprojectors of the type disclosed in my commonly assigned U.S. Pat. No.3,558,208, entitled Control Device for Self-Threading Motion PictureProjector," the disclosure of such patent being incorporated into thisdisclosure. More particularly, the invention relates to the provision ofsuch a projector with an improved control device which prevents the filmstripping and threading mechanism (also known as the film feedingmechanism) from being retained in an active condition when there is lessthan a minimum length of film on the supply reel, or in the absence of asupply reel.

2. Description of the Prior Art The film stripping and threadingmechanism for motion picture projectors as disclosed in myaboveidentified patent includes a drive member which is movable to anactive position at which a longitudinally movable endless belt is inperipheral engagement with a roll of film wound onto a supply reel in afilm cartridge, thereby imparting unwinding rotation to that roll. Astripper finger is also moved into peripheral engagement with the filmroll to separate the leading end of the film from the roll and to guideit along a predetermined threading path partially defined between thestripper finger and the belt member. By this means, the leading end ofthe film is caused toenter a film gate of the projector, where it isengaged by a pull down claw or other equivalent film-advancing memberwhich thereupon advances it intermittently through thefilm gate. f

The drive member and stripper finger must be retained in engagement withthe roll and, upon completeion of the film threading operation (i.e.,upon engage ment of the film by the film-advancing member), the drivemember and the stripper finger must be moved out of peripheralengagement with the film roll before the film is displayed. In theprojector disclosed in the aforementioned U.S. patent, this isaccomplished by means of a latch mechanism which retains the drivemember and the stripper finger in their respective active positionsuntil the latch member is released in response to the resultingtensioning of the film between the gate and the film supply reel,thereby permitting the drive member and the stripper finger to moveoutof engagement with the film roll. Additionally, the. latch member can bereleased manually at any time by means of the same operating memberemployed to initiate the film threading operation. y t i Inself-threading cartridge-loaded motion picture projectors of this type,the film stripping and threading is carried in a cartridge, the operatormay not notice that the stripper finger and belt member is within thecartridge. If the operator attempts to remove the cartridge at this timeto find the cause of the problem, damage may result to the projectormechanism.

SUMMARY OF THE INVENTION It is an object of the present invention toavoid latching of a film stripping and threading mechanism in theabove-described type of projector in its active position if there isless than a minimum diameter film roll on the supply reel or in theabsence of any supply reel on the projector.

In accordance with the above object, I have provided a simple andreliable control device adapted to be incorporated in theabove-described type of projector wherein in response to manual movementof an operating member, the film stripping and threading mechanism ismoved to its active position where it is releas ably retained inengagement with the film roll by a latch member of a control device.Should the film threading operation be initiated when there is less thana minimum length of film on the supply :roll or when there is no supplyreel on the projector, the latch member will be ineffective to retainthe film stripping and threading elements in their respective activepositions.

The invention, and its objects and advantages, will become more apparentin the detailed description of the preferred embodiment presentedbelow.-

BRIEF DESCRIPTION OF THE DRAWINGS In the detailed description of thepreferred embodiment'of the invention, presented below, reference ismade to the accompanying drawings, in which:

FIG. 1 is an elevational view of a portion of a selfthreading motionpicture projector taken from inside the projector to show thearrangement of internally lomechanism will not move into contact withthe film roll to remove the leading end of the roll from the reel if thefilm is less than a minimum length. If the mechanism is moved to itsactive position when the supply roll is of less than a minimum diameter,or if there is not supply reel on the projector, film may not bethreaded to the gate and in such cases there will be no film tension tocated components of the film stripping and threading mechanism inassociation with a control device according to the present invention; a

FIG. 2 is a view from the same viewpoint as FIG. I, depicting therelative positions assumed by the various illustrated elements of thefilm stripping and threading mechanism and of the subject control deviceduring the film stripping and threading phase of the operating cycle ofthe projector;

FIG. 3 is a view similar to FIG. 2 and shows the relative positions ofthe illustrated elements when there is less than a minimum length offilm on the supply reel during the film stripping and threading phase ofthe operating cycle of the projector; and

FIG. 4 is a perspective view of the latch member of the control deviceaccording to. the present invention.

' DESCRIPTION OF THE PREFERRED EMBODIMENT understanding the presentinvention. It will be understood, however, thatsuch components arecompletely compatible with the subject control device and have beendeleted from the present disclosure only for the purposes of clarity.Some of the elements shown in the accompanying drawings are identical tocorresponding elements in the patent, and these elements have beenreferred to by the same reference numerals as were used in the patent.These numerals have been identified in the present application by theplacement of a prime mark adjacent thereto. Other elements shown in theaccompanying drawings correspond generally to elements shown in thepatent but have been modified to varying extents. These modifiedelements have been given the same reference numerals as were used in thepatent but without a prime mark. Certain other features of the presentinvention do not have corresponding parts in the patent, and theseelements have been referred to by reference numerals followed by thesuffix a.

The illustrative projector comprises a frame plate 1 1 that may bedisposed in a vertical plane. A roll of film 21 is shown wound onto afilm supply reel 22', which is releasably supported for rotation on theprojector by a rotatable spindle 23', for example.

When the film roll is initially mounted on the projector, the leadingend of the film is separated from the film roll and fed along a guidepath to a film gate where it will be engaged by a film pull-down claw,not shown, which thereafter drives the film into engagement with the hubof a film take-up reel, not shown. As previously mentioned, the feedingof film to the gate is performed by a film stripping and threadingmechanism (sometimes referred to as a film feeding mechanism) comprisinga drive member 24 having a longitudinally movable endless belt, notshown, and a stripper finger 25'. Both the drive member and the stripperfinger are described in detail in US. Pat. No. 3,558,028.

Drive member 24' pivots about a drive shaft 34 between its inactiveposition shown in FIG. 1 and an active position at which it is inengagement with the roll of film on reel 22' as shown in FIG. 2. Whenthe drive member is moved to an active position, it imparts unwindingrotation to the film roll as described in the aforementioned patent. Inoperation, the film roll is rotated in an unwinding direction by thedrive member, and the film roll is engaged by stripper finger 25 so thatthe leading end of the film enages the finger and is thereby separatedfrom the roll and delivered along the guide path.

The mechanism employed to move the stripper member 25 and drive member24 subsequently into engagement with the film roll comprises athree-lobed cam member 48 (two lobes being shown) rotatably supported ona drive shaft 34 between frame plate 11 and a carrier plate, not shown.A clutch-operating means includes a lever 57 pivotally mounted on thecarrier plate by a pin 58' and biased upwardly (clockwise) by a spring59'. A pair of ears 6] and 63' on lever 57 control a clutch member, notshown, in a manner fully described in US. Pat. No. 3,558,028 toselectively couple cam member 48' to drive shaft 34 to rotate the cammember between an initial position shown in FIG. 1 and an intermediateposition shown in FIG. 2. Upon movement of lever 57 to its positionshown in FIG. 2, cam member 48' is coupled to shaft 34' to rotate thecam member through an angle of approximately 120 whereupon the cammember is again immobilized at its intermediate position. Thereafter,movement of lever 57 back to its former position similarly causes thecam member to be driven through an angle of approximately 240 to restoreit to its initial position.

The position of drive member 24' is controlled by cam member 48 throughthe agency of a control lever 74 which is pivoted to a support stud 75and provided with a cam follower ear 76 biased toward engagement with acam lob 77' by a spring 78. A positioning stud 79', rigidly attached todrive member 24, is received in a slot 81' at the corresponding end ofthe control lever, thereby correlating the position of the drive memberwith that of the control lever.

Except during the film stripping and threading operation, lever 57 isangularly oriented as shown in FIG. 1, whereby the drive member and thestripper finger are retained in their respective inactive positions.Upon movement of lever 57 to its lower position shown in FIG. 2, camlobe 77' presents a decreasingly smaller radius to cam follower ear 76'of control lever 74 so that spring 78' can pivot the slotted end of thecontrol lever upwardly to thereby rotate the drive member into resilientdriving engagement with the film roll. At such time stripper finger 25'is also moved into engagement with the film roll by means fully setforth in US. Pat. No. 3,558,028.

As explained in the aforementioned patent, during the projection of thefilm, a snubber member between the supply reel and the gate is free topivot downwardly against the influence of a relatively weak leaf springto absorb momentary fluctuations in the film tension. The trailing endof the film is attached to the film supply reel 22 so that the film isdrawn taunt between the gate and that reel when all of the availablefilm has been displayed. When this occurs, the snubber member is pivotedto its lowermost position so that it engages and depresses a triggermember 87' to initiate the rewinding of the film by effecting automaticadjustment of a rewind mechanism, not shown, which opens the film gateand imparts film rewinding rotation to the film supply reel. During thefilm stripping and threading operation, however, the snubber member mustbe retained in its raised position with greater force than that affordedby its spring in order to insure that the leading end of the filmstripwill be guided positively into the film gate. This is accomplished inthe apparatus according to the present invention by means of a snubberarm 88 which is biased upwardly above a pivot pin 89' by a spring 90 tourge a shoe 91a toward engagement with trigger member 87'. A camfollower car 93' on am 88 is adapted to engage a lobe 94' on cam member48, holding the arm in its inoperative position as shown in FIG. 1whenever the cam member is in its initial position. As the cam memberrotates to its FIG. 2 or intermediate position, as previously described,the decreased radius of the portion of cam lobe 94' adjacent camfollower car 93' allows spring 90 to pivot arm 88 upwardly until shoe910 contacts trigger member 87' so that the film snubber member mustovercome the combined force of its own spring and spring 90' to depresstrigger member 87.

The position of lever 57 is established by an operating lever 95a whichis pivotally mounted on the carrier plate by pin 58' and forms anotherpart of the clutchoperating means. A tab 96a on operating lever 95apasses through an opening 97a in lever 57 so that by manually movingoperating lever 95a downwardly against the force of a spring 980, lever57 is moved from its position shown in FIG. 1 to its position shown inFIG. 2 to initiate the film stripping and threading operation byinitiating rotation of the cam member from its initial position to itsintermediate position.

Snubber arm 88 carries a latching arm 99a with a bent tab 100a.Operating lever 950 also has a bent tab 102a. When the operator manuallydepresses operating lever 95a, lever 57 is pivoted downwardly, aspreviously explained, thereby initiating rotation of the cam member toits intermediate position. As soon as rotation proceeds, cam lobe 94allows spring 90' to pivot snubber arm 88 to the position shown in FIG.2, as also explained above, and in so doing moves latching arm 99a tothe position illustrated in that same figure so that tab 100a engagestab 102a of the operating lever and the engagement between parts 95a and99a and the force exerted by spring 90 hold operating lever 95a andlever 57 latched in their lower position in opposition to springs 59'and 98a. Thus, as soon as such engagement of tabs 100a and 102a has beenestablished, the operator can release operating lever 95a withoutinterrupting the continuing performance of the film stripping andthreading operation.

When the completion of the film stripping and threading operation hasbrought the leading end of the film into contact with the pull-downclaw, the longitudinal movement imparted to the film by the claw exceedsthe rate in which the film can be unwound from the film roll byengagement of the slower moving drive belt with the film. Therefore,sufficient tension is developed in the film between the gate and thefilm cartridge to depress trigger member 87' by overpowering spring 90'and the spring associated with the snubber. Before trigger member 87 ismoved to the position at which it initiates the film-rewinding operationof the projector, the accompanying rotation of snubber arm 88 displaceslatching arm 99a to disengage tab 100a from tab 102a; thereby allowingsprings 59 and 98a to raise operating lever 95a and lever 57 so that thecam member will return to its initial position by completing a singlerevolution. Therefore, the illustrated mechanism is restoredautomatically to the condition depicted in FIG. 1 to allow theprojection of the film to proceed. Provision may be made for manuallydepressing trigger member 87 to enable the operator to discontinue thefilm stripping and threading operation at any time.

Referring to FIG. 3, I have shown a supply reel upon which less than aminimum length of film has been wound. If such a reel were mounted onthe projector, or if there was no reel on the projector, and the filmstripping and threading operation initiated, the mechanism might beincapable of withdrawing the leading.

end of the film from the cartridge. As such, were the latch mechanism tobe engaged, it would remain engaged with no film in the guide path todepress trigger member 87'. Although, as mentioned hereinbefore, theoperator could manually depress the trigger member to return themechanism to its initial position shown in FIG. I, this may causeconfusion in cases where the operator is unfamiliar with the projectorand has not carefully read the manual. As such, I have provided means toprevent the latch mechanism from becoming engaged in such situations sothat the cam member is immediately returned to its initial position assoon as the operator releases operating lever 95a.

In accordance with one feature of the present inven- 6 tion, I haveprovided aligned teeth 103a and 104a on snubber arm 88 and control lever74', respectively. When snubber arm 88 has been allowed to move to itsposition shown in FIG. 2 by rotation of cam lobe 94, tooth 103a lieswithin the path of tooth 104a on control lever '74 as that lever ismoved upwardly by spring 78 as cam lobe 77' presents a decreasing radiusto cam follower ear 76'. Normally, when a film reel having a roll offilm of greater diameter than the minimum which can be successfully usedin a projector is mounted on spindle 23', drive member 24' engages theperipheral surface of the roll to halt further upward movement of tooth104a. However, should the mechanism be operated in an attempt towithdraw the leading end of a filmstrip from a roll of less than theminimum diameter, as shown in FIG. 3, drive member 24' continues to movetoward spindle 23' thereby permitting lever 74' to move counterclockwiseuntil tooth 104a engages tooth 103a. Further movement of the drivemember causes tooth 104a to rotate snubber arm 88 against the force ofspring 90 to move latch arm 99a to the right as viewed in FIG. 3. Thismovement causes tab 100a to be withdrawn from the above tab 102a,thereby releasing operating lever a and lever 57 so that the cam memberwill return to its initial position by completing a single revolution.

Thus, by the present invention, the latching mechanism for retaining thefilm stripping and threading elements in their active positions isdisabled when the projector is operated with a supply reel containingless than a minimum length of film thereon or when the projector isoperated without a supply reel.

The invention has been described in detail with particular reference toa preferred embodiment thereof, but it will be understood thatvariations and modifications can beeffected within the spirit and scopeof the invention.

I claim: 1. In a control device for apparatus having (1 means forsupporting a supply roll of web material comprising an elongated stripof web material having a leading end, (2) a stripping and threadingmechanism adjustable to an active condition for feeding the leading endof the web material from a supported supply roll of at least apredetermined diameter and to an inactive condition, (3) operating meansmovable to a. first position and to a second position for adjusting; thestripping and threading mechanism respectively to its inactive andactive conditions, (4) resilient means for biasing said operating meanstoward said first position, and (5 means for releasably latching saidloperating means in said second position, the improvement comprising:

detecting means for sensing the movement of said operating means beyondsaid second position towards said supporting means, thereby detectingthe presence on said supporting means of a supply roll having less thansaid predetermined diameter or the absence on said supporting means of asupply roll; and

means responsive to said detecting means for preventing said latchingmeans from latching said operating meansin said second position whensaid detecting means senses the movement of said operating means beyondsaid second position towards said support means.

2. The improvement defined in claim 1 further comprising meansresponsive to the feeding of the leading end of the web material fromthe supply roll for releasing said latching means.

3. The improvement as defined in claim 1 wherein:

said latching means comprises a latching arm movable into engagementwith said operating means in response to movement of said operatingmeans from its first position toward said second position to blockmovement of said operating means to said first position; and said meansresponsive to said detecting means comprises means for preventingmovement of said latching arm into engagement with said operating meanswhen a supply roll of at least said predetermined diameter is notsupported on said apparatus. 4. In a control device for a motion pictureprojector of the type having 1) means for supporting a film supply rollcomprising an elongate strip of film having a leading end, (2) astripping and threading mechanism adjustable to an active condition forfeeding the leading end of the film from a supported supply roll of atleast a predetermined diameter and to an inactive condition, (3) arotating drive shaft, (4) a rotatable cam member, (5) clutch-operatingmeans coupled to the shaft and to the cam member and movable between afirst position and a second position for effecting rotation of said cammember by said drive shaft to predetermined initial and intermediaterotative locations corresponding respectively to said first and secondpositions of said clutchoperating means, (6) control means operated bysaid cam member for adjusting said stripping and threading mechanism tosaid first condition in response to rotation of said cam member to saidinitial rotative location and to said second condition in response torotation of said cam member to said intermediate rotative location, and(7) a latch member movable into operative latching engagement with saidclutch-operating means at said second position thereof in response torotation of said cam member from said initial rotative location towardsaid intermediate rotative location to releasably retain saidclutch-operating means in said second position; the improvementcomprising:

detecting means for sensing the presence of a supply roll on saidsupporting means having less than said predetermined diameter and forsensing the absence on said supporting means of a film supply roll; and

means responsive to said detecting means for preventing movement of saidlatch member into latching engagement with said clutch-operating meanswhen said detecting means senses the presence of a supply roll havingless than said predetermined diameter or when said detecting meanssenses the absence of a supply roll.

5. The improvement defined in claim 4 wherein said means for preventingmovement of said latch member comprises means on said control means forblocking such movment of said latch member.

6. In a control device for apparatus having (1) means for supporting asupply roll of web material comprising an elongate strip of web materialhaving a leading end, 2) a web stripping and threading mechanism movablebetween (a) first and second positions wherein the mechanism isineffective to engage the supply roll to feed web material from thesupply roll, and (b) each of a plurality of web feeding positionsbetween its first and second positions wherein the mechanism iseffective to engage the supply roll and feed the leading end of the webmaterial from a web supply roll which may vary in size from a relativelysmall diameter roll to a relatively large diameter roll, (3) operatingmeans movable between a first position and a second position for movingthe mechanism between its first and second positions, and resilientmeans for urging said operating means toward its first position, theimprovement comprising:

latch means for releasably latching said operating means in at least oneposition between its first and second positions thereby to latch saidstripping and threading mechanism in a web feeding position; and

means coupled to said operating means and to said latch means andeffective in response to movement of said operating means to its secondposition for preventing said latch means for latching.

1. In a control device for apparatus having (1 ) means for supporting a supply roll of web material comprising an elongated strip of web material having a leading end, (2) a stripping and threading mechanism adjustable to an active condition for feeding the leading end of the web material from a supported supply roll of at least a predetermined diameter and to an inactive condition, (3) operating means movable to a first position and to a second position for adjusting the stripping and threading mechanism respectively to its inactive and active conditions, (4) resilient means for biasing said operating means toward said first position, and (5 ) means for releasably latching said operating means in said second position, the improvement comprising: detecting means for sensing the movement of said operating means beyond said second position towards said supporting means, thereby detecting the presence on said supporting means of a supply roll having less than said predetermined diameter or the absence on said supporting means of a supply roll; and means responsive to said detecting means for preventing said latching means from latching said operating means in said second position when said detecting means senses the movement of said operating means beyond said second position towards said support means.
 2. The improvement defined in claim 1 further comprising means responsive to the feeding of the leading end of the web material from the supply roll for releasing said latching means.
 3. The improvement as defined in claim 1 wherein: said latching means comprises a latching arm movable into engagement with said operating means in response to movement of said operating means from its first position toward said second position to block movement of said operating means to said first position; and said means responsive to said detecting means comprises means for preventing movement of said latching arm into engagement with said operating means when a supply roll of at least said predetermined diameter is not supported on said apparatus.
 4. In a control device for a motion picture projector of the type having (1) means for supporting a film supply roll comprising an elongate strip of film having a leading end, (2) a stripping and threading mechanism adjustable to an active condition for feeding the leading end of the film from a supported supply roll of at least a predetermined diameter and to an inactive condition, (3) a rotating drive shaft, (4) a rotatable cam member, (5) clutch-operating means coupled to the shaft and to the cam member and movable between a first position and a second position for effecting rotation of said cam member by said drive shaft to predetermined initial and intermediate rotative locations corresponding respectively to said first and second positions of said clutch-operating means, (6) control means operated by said cam member for adjusting said strippIng and threading mechanism to said first condition in response to rotation of said cam member to said initial rotative location and to said second condition in response to rotation of said cam member to said intermediate rotative location, and (7) a latch member movable into operative latching engagement with said clutch-operating means at said second position thereof in response to rotation of said cam member from said initial rotative location toward said intermediate rotative location to releasably retain said clutch-operating means in said second position; the improvement comprising: detecting means for sensing the presence of a supply roll on said supporting means having less than said predetermined diameter and for sensing the absence on said supporting means of a film supply roll; and means responsive to said detecting means for preventing movement of said latch member into latching engagement with said clutch-operating means when said detecting means senses the presence of a supply roll having less than said predetermined diameter or when said detecting means senses the absence of a supply roll.
 5. The improvement defined in claim 4 wherein said means for preventing movement of said latch member comprises means on said control means for blocking such movment of said latch member.
 6. In a control device for apparatus having (1) means for supporting a supply roll of web material comprising an elongate strip of web material having a leading end, (2) a web stripping and threading mechanism movable between (a) first and second positions wherein the mechanism is ineffective to engage the supply roll to feed web material from the supply roll, and (b) each of a plurality of web feeding positions between its first and second positions wherein the mechanism is effective to engage the supply roll and feed the leading end of the web material from a web supply roll which may vary in size from a relatively small diameter roll to a relatively large diameter roll, (3) operating means movable between a first position and a second position for moving the mechanism between its first and second positions, and resilient means for urging said operating means toward its first position, the improvement comprising: latch means for releasably latching said operating means in at least one position between its first and second positions thereby to latch said stripping and threading mechanism in a web feeding position; and means coupled to said operating means and to said latch means and effective in response to movement of said operating means to its second position for preventing said latch means for latching. 